A hybrid electric or battery electric vehicle transmission typically includes one or more high-voltage polyphase electric machines in the form of a motor generator unit or an electric traction motor. Electric machines deliver/charge power to or draw power from a rechargeable direct current (DC) battery pack. The energized electric machines adjust torques of the various gear sets of the transmission to achieve optimal system efficiency. A DC boost converter is typically used to increase the battery output voltage to a level suitable for use by the electric machines.
Semiconductor switches of a power inverter module are controlled via pulse-width modulation or other switching control signals to convert the boosted battery output voltage from the DC boost converter into an alternating current (AC) output voltage. The AC output voltage from the power inverter module is ultimately transmitted to the individual phase windings of the electric machine. The energized electric machine powers the drivetrain of the vehicle.